Paul McGowan / PS AUDIO:
When we built Music Room One we made a point of electrifying it properly: Dedicated circuits with heavy gauge wire. Had we the time and budget we would have also used grounded conduit as a shield against noise.
The importance of a proper AC foundation cannot be understated. The two properties we focused on, wire gauge and single-run, are the most important.
Wire gauge matters because of lowered resistance. When we pass current through a wire we drop voltage. The heavier gauge the wire, the less voltage is dropped. If I were able to use a copper wire pair the size of a cow’s leg I would. Overkill is not an appropriate term when it comes to selecting thick copper wire because it suggests the effort isn’t worth it. It is. We draw the line at 10 gauge (the lower the gauge number the thicker the wire) for practical reasons. Too thick and it won’t fit into any receptacle.
Where wire gauge is important for the unimpeded flow of power, dedicating a single circuit to each receptacle helps with noise. The technique of running a separate wire to each duplex receptacle lowers noise because of the separate ground wire. Each “home run” of wire, as it is known, has both legs of the AC circuit as well as a separate third-wire ground. It is this third-wire ground that keeps equipment noise from contaminating other equipment. When nothing is shared, one piece cannot contaminate the others in the system.
If you want some further information I have put together another video you can watch here.